feature gate PyCell (#4177)

* feature gate `PyCell`

* feature gate `HasPyGilRef` completely

* bump version

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "pyo3"
-version = "0.21.2"
+version = "0.22.0-dev"
 description = "Bindings to Python interpreter"
 authors = ["PyO3 Project and Contributors <https://github.com/PyO3>"]
 readme = "README.md"
@@ -20,10 +20,10 @@ libc = "0.2.62"
 memoffset = "0.9"
 
 # ffi bindings to the python interpreter, split into a separate crate so they can be used independently
-pyo3-ffi = { path = "pyo3-ffi", version = "=0.21.2" }
+pyo3-ffi = { path = "pyo3-ffi", version = "=0.22.0-dev" }
 
 # support crates for macros feature
-pyo3-macros = { path = "pyo3-macros", version = "=0.21.2", optional = true }
+pyo3-macros = { path = "pyo3-macros", version = "=0.22.0-dev", optional = true }
 indoc = { version = "2.0.1", optional = true }
 unindent = { version = "0.2.1", optional = true }
 
@@ -62,7 +62,7 @@ rayon = "1.6.1"
 futures = "0.3.28"
 
 [build-dependencies]
-pyo3-build-config = { path = "pyo3-build-config", version = "=0.21.2", features = ["resolve-config"] }
+pyo3-build-config = { path = "pyo3-build-config", version = "=0.22.0-dev", features = ["resolve-config"] }
 
 [features]
 default = ["macros"]
@@ -106,7 +106,7 @@ generate-import-lib = ["pyo3-ffi/generate-import-lib"]
 auto-initialize = []
 
 # Allows use of the deprecated "GIL Refs" APIs.
-gil-refs = []
+gil-refs = ["pyo3-macros/gil-refs"]
 
 # Enables `Clone`ing references to Python objects `Py<T>` which panics if the GIL is not held.
 py-clone = []

guide/src/class.md

@@ -1307,6 +1307,7 @@ struct MyClass {
 impl pyo3::types::DerefToPyAny for MyClass {}
 
 # #[allow(deprecated)]
+# #[cfg(feature = "gil-refs")]
 unsafe impl pyo3::type_object::HasPyGilRef for MyClass {
     type AsRefTarget = pyo3::PyCell<Self>;
 }

guide/src/migration.md

@@ -1609,7 +1609,7 @@ For more, see [the constructor section](class.md#constructor) of this guide.
 <details>
 <summary><small>Click to expand</small></summary>
 
-PyO3 0.9 introduces [`PyCell`], which is a [`RefCell`]-like object wrapper
+PyO3 0.9 introduces `PyCell`, which is a [`RefCell`]-like object wrapper
 for ensuring Rust's rules regarding aliasing of references are upheld.
 For more detail, see the
 [Rust Book's section on Rust's rules of references](https://doc.rust-lang.org/book/ch04-02-references-and-borrowing.html#the-rules-of-references)
@@ -1788,7 +1788,6 @@ impl PySequenceProtocol for ByteSequence {
 
 [`FromPyObject`]: {{#PYO3_DOCS_URL}}/pyo3/conversion/trait.FromPyObject.html
 [`PyAny`]: {{#PYO3_DOCS_URL}}/pyo3/types/struct.PyAny.html
-[`PyCell`]: {{#PYO3_DOCS_URL}}/pyo3/pycell/struct.PyCell.html
 [`PyBorrowMutError`]: {{#PYO3_DOCS_URL}}/pyo3/pycell/struct.PyBorrowMutError.html
 [`PyRef`]: {{#PYO3_DOCS_URL}}/pyo3/pycell/struct.PyRef.html
 [`PyRefMut`]: {{#PYO3_DOCS_URL}}/pyo3/pycell/struct.PyRef.html

pyo3-build-config/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "pyo3-build-config"
-version = "0.21.2"
+version = "0.22.0-dev"
 description = "Build configuration for the PyO3 ecosystem"
 authors = ["PyO3 Project and Contributors <https://github.com/PyO3>"]
 keywords = ["pyo3", "python", "cpython", "ffi"]

pyo3-ffi/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "pyo3-ffi"
-version = "0.21.2"
+version = "0.22.0-dev"
 description = "Python-API bindings for the PyO3 ecosystem"
 authors = ["PyO3 Project and Contributors <https://github.com/PyO3>"]
 keywords = ["pyo3", "python", "cpython", "ffi"]
@@ -38,7 +38,7 @@ abi3-py312 = ["abi3", "pyo3-build-config/abi3-py312"]
 generate-import-lib = ["pyo3-build-config/python3-dll-a"]
 
 [build-dependencies]
-pyo3-build-config = { path = "../pyo3-build-config", version = "=0.21.2", features = ["resolve-config"] }
+pyo3-build-config = { path = "../pyo3-build-config", version = "=0.22.0-dev", features = ["resolve-config"] }
 
 [lints]
 workspace = true

pyo3-macros-backend/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "pyo3-macros-backend"
-version = "0.21.2"
+version = "0.22.0-dev"
 description = "Code generation for PyO3 package"
 authors = ["PyO3 Project and Contributors <https://github.com/PyO3>"]
 keywords = ["pyo3", "python", "cpython", "ffi"]
@@ -16,7 +16,7 @@ edition = "2021"
 [dependencies]
 heck = "0.5"
 proc-macro2 = { version = "1", default-features = false }
-pyo3-build-config = { path = "../pyo3-build-config", version = "=0.21.2", features = ["resolve-config"] }
+pyo3-build-config = { path = "../pyo3-build-config", version = "=0.22.0-dev", features = ["resolve-config"] }
 quote = { version = "1", default-features = false }
 
 [dependencies.syn]
@@ -29,3 +29,4 @@ workspace = true
 
 [features]
 experimental-async = []
+gil-refs = []

pyo3-macros-backend/src/module.rs

@@ -384,6 +384,11 @@ fn process_functions_in_module(options: &PyModuleOptions, func: &mut syn::ItemFn
     let Ctx { pyo3_path } = ctx;
     let mut stmts: Vec<syn::Stmt> = Vec::new();
 
+    #[cfg(feature = "gil-refs")]
+    let imports = quote!(use #pyo3_path::{PyNativeType, types::PyModuleMethods};);
+    #[cfg(not(feature = "gil-refs"))]
+    let imports = quote!(use #pyo3_path::types::PyModuleMethods;);
+
     for mut stmt in func.block.stmts.drain(..) {
         if let syn::Stmt::Item(Item::Fn(func)) = &mut stmt {
             if let Some(pyfn_args) = get_pyfn_attr(&mut func.attrs)? {
@@ -394,7 +399,7 @@ fn process_functions_in_module(options: &PyModuleOptions, func: &mut syn::ItemFn
                     #wrapped_function
                     {
                         #[allow(unknown_lints, unused_imports, redundant_imports)]
-                        use #pyo3_path::{PyNativeType, types::PyModuleMethods};
+                        #imports
                         #module_name.as_borrowed().add_function(#pyo3_path::wrap_pyfunction!(#name, #module_name.as_borrowed())?)?;
                     }
                 };

pyo3-macros-backend/src/pyclass.rs

@@ -1307,11 +1307,19 @@ fn impl_pytypeinfo(
         quote! { ::core::option::Option::None }
     };
 
-    quote! {
+    #[cfg(feature = "gil-refs")]
+    let has_py_gil_ref = quote! {
         #[allow(deprecated)]
         unsafe impl #pyo3_path::type_object::HasPyGilRef for #cls {
             type AsRefTarget = #pyo3_path::PyCell<Self>;
         }
+    };
+
+    #[cfg(not(feature = "gil-refs"))]
+    let has_py_gil_ref = TokenStream::new();
+
+    quote! {
+        #has_py_gil_ref
 
         unsafe impl #pyo3_path::type_object::PyTypeInfo for #cls {
             const NAME: &'static str = #cls_name;

pyo3-macros/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "pyo3-macros"
-version = "0.21.2"
+version = "0.22.0-dev"
 description = "Proc macros for PyO3 package"
 authors = ["PyO3 Project and Contributors <https://github.com/PyO3>"]
 keywords = ["pyo3", "python", "cpython", "ffi"]
@@ -17,12 +17,13 @@ proc-macro = true
 multiple-pymethods = []
 experimental-async = ["pyo3-macros-backend/experimental-async"]
 experimental-declarative-modules = []
+gil-refs = ["pyo3-macros-backend/gil-refs"]
 
 [dependencies]
 proc-macro2 = { version = "1", default-features = false }
 quote = "1"
 syn = { version = "2", features = ["full", "extra-traits"] }
-pyo3-macros-backend = { path = "../pyo3-macros-backend", version = "=0.21.2" }
+pyo3-macros-backend = { path = "../pyo3-macros-backend", version = "=0.22.0-dev" }
 
 [lints]
 workspace = true

pyproject.toml

@@ -3,7 +3,7 @@
 
 [tool.towncrier]
 filename = "CHANGELOG.md"
-version = "0.21.2"
+version = "0.22.0-dev"
 start_string = "<!-- towncrier release notes start -->\n"
 template = ".towncrier.template.md"
 title_format = "## [{version}] - {project_date}"

src/conversion.rs

@@ -5,14 +5,12 @@ use crate::inspect::types::TypeInfo;
 use crate::pyclass::boolean_struct::False;
 use crate::types::any::PyAnyMethods;
 use crate::types::PyTuple;
-use crate::{
-    ffi, Borrowed, Bound, Py, PyAny, PyClass, PyNativeType, PyObject, PyRef, PyRefMut, Python,
-};
+use crate::{ffi, Borrowed, Bound, Py, PyAny, PyClass, PyObject, PyRef, PyRefMut, Python};
 #[cfg(feature = "gil-refs")]
 use {
     crate::{
         err::{self, PyDowncastError},
-        gil,
+        gil, PyNativeType,
     },
     std::ptr::NonNull,
 };
@@ -221,6 +219,7 @@ pub trait FromPyObject<'py>: Sized {
     ///
     /// Implementors are encouraged to implement `extract_bound` and leave this method as the
     /// default implementation, which will forward calls to `extract_bound`.
+    #[cfg(feature = "gil-refs")]
     fn extract(ob: &'py PyAny) -> PyResult<Self> {
         Self::extract_bound(&ob.as_borrowed())
     }

src/err/mod.rs

@@ -3,11 +3,13 @@ use crate::panic::PanicException;
 use crate::type_object::PyTypeInfo;
 use crate::types::any::PyAnyMethods;
 use crate::types::{string::PyStringMethods, typeobject::PyTypeMethods, PyTraceback, PyType};
+#[cfg(feature = "gil-refs")]
+use crate::PyNativeType;
 use crate::{
     exceptions::{self, PyBaseException},
     ffi,
 };
-use crate::{Borrowed, IntoPy, Py, PyAny, PyNativeType, PyObject, Python, ToPyObject};
+use crate::{Borrowed, IntoPy, Py, PyAny, PyObject, Python, ToPyObject};
 use std::borrow::Cow;
 use std::cell::UnsafeCell;
 use std::ffi::CString;
@@ -47,11 +49,13 @@ pub type PyResult<T> = Result<T, PyErr>;
 
 /// Error that indicates a failure to convert a PyAny to a more specific Python type.
 #[derive(Debug)]
+#[cfg(feature = "gil-refs")]
 pub struct PyDowncastError<'a> {
     from: &'a PyAny,
     to: Cow<'static, str>,
 }
 
+#[cfg(feature = "gil-refs")]
 impl<'a> PyDowncastError<'a> {
     /// Create a new `PyDowncastError` representing a failure to convert the object
     /// `from` into the type named in `to`.
@@ -64,7 +68,6 @@ impl<'a> PyDowncastError<'a> {
 
     /// Compatibility API to convert the Bound variant `DowncastError` into the
     /// gil-ref variant
-    #[cfg(feature = "gil-refs")]
     pub(crate) fn from_downcast_err(DowncastError { from, to }: DowncastError<'a, 'a>) -> Self {
         #[allow(deprecated)]
         let from = unsafe { from.py().from_borrowed_ptr(from.as_ptr()) };
@@ -1012,8 +1015,10 @@ impl<'a> std::convert::From<PyDowncastError<'a>> for PyErr {
     }
 }
 
+#[cfg(feature = "gil-refs")]
 impl<'a> std::error::Error for PyDowncastError<'a> {}
 
+#[cfg(feature = "gil-refs")]
 impl<'a> std::fmt::Display for PyDowncastError<'a> {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> Result<(), std::fmt::Error> {
         display_downcast_error(f, &self.from.as_borrowed(), &self.to)

src/exceptions.rs

@@ -146,6 +146,7 @@ macro_rules! import_exception_bound {
 
         // FIXME remove this: was necessary while `PyTypeInfo` requires `HasPyGilRef`,
         // should change in 0.22.
+        #[cfg(feature = "gil-refs")]
         unsafe impl $crate::type_object::HasPyGilRef for $name {
             type AsRefTarget = $crate::PyAny;
         }

src/impl_/deprecations.rs

@@ -19,6 +19,7 @@ pub struct NotAGilRef<T>(std::marker::PhantomData<T>);
 
 pub trait IsGilRef {}
 
+#[cfg(feature = "gil-refs")]
 impl<T: crate::PyNativeType> IsGilRef for &'_ T {}
 
 impl<T> GilRefs<T> {

src/impl_/pyclass.rs

@@ -1,3 +1,5 @@
+#[cfg(feature = "gil-refs")]
+use crate::PyNativeType;
 use crate::{
     exceptions::{PyAttributeError, PyNotImplementedError, PyRuntimeError, PyValueError},
     ffi,
@@ -7,8 +9,7 @@ use crate::{
     pyclass_init::PyObjectInit,
     types::any::PyAnyMethods,
     types::PyBool,
-    Borrowed, Py, PyAny, PyClass, PyErr, PyMethodDefType, PyNativeType, PyResult, PyTypeInfo,
-    Python,
+    Borrowed, Py, PyAny, PyClass, PyErr, PyMethodDefType, PyResult, PyTypeInfo, Python,
 };
 use std::{
     borrow::Cow,
@@ -168,7 +169,12 @@ pub trait PyClassImpl: Sized + 'static {
 
     /// The closest native ancestor. This is `PyAny` by default, and when you declare
     /// `#[pyclass(extends=PyDict)]`, it's `PyDict`.
+    #[cfg(feature = "gil-refs")]
     type BaseNativeType: PyTypeInfo + PyNativeType;
+    /// The closest native ancestor. This is `PyAny` by default, and when you declare
+    /// `#[pyclass(extends=PyDict)]`, it's `PyDict`.
+    #[cfg(not(feature = "gil-refs"))]
+    type BaseNativeType: PyTypeInfo;
 
     /// This handles following two situations:
     /// 1. In case `T` is `Send`, stub `ThreadChecker` is used and does nothing.